Add ROCm_whisper.md (Docker + native install guide) and docker/Dockerfile.rocm
based on rocm/pytorch:rocm7.2.4 (PyTorch 2.10.0) that installs the official
CTranslate2 v4.8.0 ROCm wheel. The default faster_whisper backend runs on AMD
GPUs out of the box with no code changes.
Tested on Radeon AI PRO R9700 (gfx1201) and Ryzen AI Max+ 395 / Radeon 8060S
(gfx1151) with ROCm 7.2.4.
Addresses #520.
Kaihui-AMD